Inspired by Lord Ashcroft's polling in Feltham and Heston, would be a poll comparing Boris Johnson, Ken Livingstone and AN Other Labour Candidate.
The reason for this being a fair amount of the internal Labour party arguments about Ken's popularity. The poll above confirms that Labour are ahead of the Tories, and that Ken is behind Boris, what we don't know is whether this is because Boris is more popular than the Tories or Ken is less popular than Labour. The view that appeals to my politics is that Boris, as a larger than life figure enjoys a large popular vote that extends to those who would normally support Labour, Ken's appeal has faded, but he is not really less popular than Labour.
Like I say, only my personal opinion here but it would be good to sort this one out once and for all.